Removing items from your website is very simple.

1.  Login to the admin of your website, from the dashboard, choose Catalog and then Items.

2.  Using the filter at the top of the page, locate the item or items that you want to disable..  You can search for the SKU, or use the drop downs to select the Vendor, Brand, or Collection to edit.

3.  Select the item from the list.. Click on the little square on the very left of each item.  You should get a check-mark on that item.

4.  Click on the "Action" drop down and select "Deactivate selected items"

5.  Finally, Click on the Apply button.

That's it!  These items will no longer be shown or searchable on your website.

BONUS!  - You can use this same technique to set witch items appear in the "Featured" section at the top of the product grid pages...